Require packages

library(utils)
library(dplyr)
library(ggplot2)
library(maps)
library(stringr)
library(readr)
library(tidyverse)
library(readxl)
library(plotly)
library(MASS)
library(kableExtra)
library(broom)
library(stargazer)

Cleaning Data

#these libraries need to be installed
#library(utils)

#read the Dataset sheet into “R”. The dataset will be called "data".
data <- read.csv("https://opendata.ecdc.europa.eu/covid19/casedistribution/csv", na.strings = "", fileEncoding = "UTF-8-BOM")

#library("dplyr") require "dplyr" package for the use of %>%
covid.data = data %>%
  rename(Date="dateRep") %>%
  rename(Region="countriesAndTerritories") %>%
  mutate(Date=as.Date(Date,format="%d/%m/%y"))%>% 
  mutate(Region = str_replace_all(Region, "_", " "))%>% 
  group_by(Region) %>%
  mutate(cases_Diff = lag(cases)-cases) %>%
  mutate(deaths_Diff = lag(deaths)-deaths) %>% 
  relocate(cases_Diff, .after = cases) %>%
  relocate(deaths_Diff, .after = deaths) %>%
  drop_na(countryterritoryCode)

Data Summary

#population dataframe
pop.data = unique(data.frame(covid.data$Region,covid.data$popData2019,covid.data$continentExp,covid.data$countryterritoryCode))
names(pop.data)=c("Region","Population2019","Continents","Codes")
pop.data = na.omit(pop.data)
pop.data = unique(pop.data)

#cases dataframe
case.data = data.frame(covid.data$Region,covid.data$cases,covid.data$countryterritoryCode) 
names(case.data) = c("Region","cases","Codes") 
case.data=aggregate(case.data$cases, by=list(Category=case.data$Region), FUN=sum)
case.data = as.data.frame(cbind(case.data,unique(covid.data$countryterritoryCode)))
names(case.data) = c("Region","cases","Codes")
case.data = na.omit(case.data)

#death dataframe
death.data = data.frame(covid.data$Region,covid.data$deaths,covid.data$countryterritoryCode) 
names(death.data) = c("Region","deaths","Codes") 
death.data=aggregate(death.data$deaths, by=list(Category=death.data$Region), FUN=sum)
death.data = as.data.frame(cbind(death.data,unique(covid.data$countryterritoryCode)))
names(death.data) = c("Region","deaths","Codes")
death.data = na.omit(death.data)

#Death/Case dataframe
death_case.data = data.frame(case.data$Region,death.data$deaths/case.data$cases,case.data$Codes)
names(death_case.data) = c("Region","Deaths/Case Ratio","Codes")

#death/pop *100
death_pop.data = data.frame(pop.data$Region,death.data$deaths/pop.data$Population2019*100,pop.data$Codes)
names(death_pop.data) = c("Region","Values","Codes")

#Land Area
Land_Area <- read_excel("Land Area.xls")
names(Land_Area) = Land_Area[3,]
Land_Area = Land_Area[-(1:3),]
Land_Area = Land_Area[,c(1,2,62,63)]

#Complete 2018
for (i in 1:nrow(Land_Area)) {
  if(is.na(Land_Area$`2018`[i])){
    Land_Area$`2018`[i] = Land_Area$`2017`[i]
  }
}
Land_Area = na.omit(Land_Area)[,-3]
names(Land_Area)[3] = "Area"

combine = full_join(pop.data, Land_Area, by=c("Codes"="Country Code"))
combine = na.omit(combine)[,-5]
pop.square = na.omit(combine)
pop.square$Area = as.numeric(pop.square$Area)

Ploting data

#Population Ditribution
pop.fig <- plot_ly(pop.data, type='choropleth', locations=pop.data$Codes, z=log2(pop.data$Population2019), text=pop.data$Region, colorscale="Blues",reversescale =T)%>%
  layout(title = 'The Logarithm of World Population in 2019')%>%
  colorbar(title = "Population Rates",limits = c(15,31))
pop.fig
#Population Density Ditribution
pop.square.fig <- plot_ly(pop.square, type='choropleth', locations=pop.square$Codes, z=log(pop.square$Population2019/pop.square$Area), text=pop.square$Region, colorscale="Blues",reversescale =T)%>%
  layout(title = 'The Logarithm of World Population Density in 2019')%>%
  colorbar(title = "Density Rates",limits = c(-2,7))
pop.square.fig
#Case Ditribution
case.fig <- plot_ly(case.data, type='choropleth', locations=case.data$Codes, z=log2(case.data$cases), text=case.data$Region, colorscale="Reds",reversescale =F)%>%
  layout(title = 'The Logarithm of World Covid-19 Cases Number')%>%
  colorbar(title = "Cases Number",limits = c(4,24))
case.fig
#Death Ditribution
death.fig <- plot_ly(death.data, type='choropleth', locations=death.data$Codes, z=log2(death.data$deaths+1), text=case.data$Region, colorscale="Reds",reversescale =F)%>%
  layout(title = 'The Logarithm of World Covid-19 Deaths Number')%>%
  colorbar(title = "Deaths Number")
death.fig
#Death/Case Ditribution
death_case.fig <- plot_ly(death_case.data, type='choropleth', locations=death_case.data$Codes, z=death_case.data$`Deaths/Case Ratio`, text=death_case.data$Region, colorscale="Reds",reversescale =F)%>%
  layout(title = 'The Ratio of World Covid-19 Deaths to Cases Number')%>%
  colorbar(title = "Ratio Number",limits = c(0,0.1))
death_case.fig
#Death/pop*100 Ditribution
death_pop.fig <- plot_ly(death_pop.data, type='choropleth', locations=death_pop.data$Codes, z=death_pop.data$`Values`, text=death_pop.data$Region, colorscale="Reds",reversescale =F)%>%
  layout(title = 'The Ratio of World Covid-19 Death/Population*100')%>%
  colorbar(title = "Ratio Number")
death_pop.fig

Modeling Preparation

#Creat Density Variable
pop.density = pop.square %>%
  mutate(Density = Population2019/Area)
pop.density = pop.density[,c(4,6)]
#Creat data for time series
covid.time = covid.data[,c(1,6,8:9,11:12)]%>%
  rename(Codes="countryterritoryCode")%>%
  inner_join(pop.density)%>%
  mutate(Region = as.factor(Region))%>%
  mutate(group_id = as.integer(Region))
groups = length(unique(covid.time$Region))

#Lag cases and deaths Difference
for (k in 1:14) {
  CASE=NULL
  for (j in 1:groups) {
    CASE=c(CASE,lag(covid.time$cases_Diff[covid.time$group_id==j],k))
  }
  covid.time = cbind(covid.time,CASE)
}
names(covid.time)[9:22]=paste("CASE_DIFF",1:14,sep="-")

for (k in 1:14) {
  DEATH=NULL
  for (j in 1:groups) {
    DEATH=c(DEATH,lag(covid.time$deaths_Diff[covid.time$group_id==j],k))
  }
  covid.time = cbind(covid.time,DEATH)
}
names(covid.time)[23:36]=paste("DEATH_DIFF",1:14,sep="-")

Modeling

#Cases on Cases
data1 = covid.time[,c(2,9:22)]
fit1.m1 <- lm(cases_Diff~., data=na.omit(data1))
fit2.m1 <- lm(cases_Diff~1, data=na.omit(data1))

step.m1 = stepAIC(fit2.m1,direction="both",scope=list(upper=fit1.m1,lower=fit2.m1),trace = FALSE)

summary(step.m1)
## 
## Call:
## lm(formula = cases_Diff ~ `CASE_DIFF-7` + `CASE_DIFF-14` + `CASE_DIFF-1` + 
##     `CASE_DIFF-8` + `CASE_DIFF-2` + `CASE_DIFF-9` + `CASE_DIFF-3` + 
##     `CASE_DIFF-12` + `CASE_DIFF-13` + `CASE_DIFF-6` + `CASE_DIFF-4` + 
##     `CASE_DIFF-10` + `CASE_DIFF-5`, data = na.omit(data1))
## 
## Residuals:
##    Min     1Q Median     3Q    Max 
## -52123    -23    -14     -3  42077 
## 
## Coefficients:
##                 Estimate Std. Error  t value Pr(>|t|)    
## (Intercept)    14.151585   3.775670    3.748 0.000178 ***
## `CASE_DIFF-7`   0.488981   0.004653  105.094  < 2e-16 ***
## `CASE_DIFF-14`  0.119312   0.003501   34.080  < 2e-16 ***
## `CASE_DIFF-1`  -0.543055   0.004280 -126.890  < 2e-16 ***
## `CASE_DIFF-8`   0.363409   0.004576   79.416  < 2e-16 ***
## `CASE_DIFF-2`  -0.422698   0.004720  -89.547  < 2e-16 ***
## `CASE_DIFF-9`   0.222387   0.004413   50.397  < 2e-16 ***
## `CASE_DIFF-3`  -0.277095   0.004681  -59.200  < 2e-16 ***
## `CASE_DIFF-12` -0.105906   0.003722  -28.450  < 2e-16 ***
## `CASE_DIFF-13` -0.103427   0.003910  -26.450  < 2e-16 ***
## `CASE_DIFF-6`   0.068494   0.004885   14.020  < 2e-16 ***
## `CASE_DIFF-4`  -0.131883   0.004187  -31.500  < 2e-16 ***
## `CASE_DIFF-10`  0.116314   0.003875   30.016  < 2e-16 ***
## `CASE_DIFF-5`  -0.066490   0.004783  -13.901  < 2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 863.4 on 52547 degrees of freedom
## Multiple R-squared:  0.5778, Adjusted R-squared:  0.5777 
## F-statistic:  5531 on 13 and 52547 DF,  p-value: < 2.2e-16
#Cases & Deaths on Cases
data2 = covid.time[,c(2,9:36)]
fit1.m2 <- lm(cases_Diff~., data=na.omit(data2))
fit2.m2 <- lm(cases_Diff~1, data=na.omit(data2))

step.m2 = stepAIC(fit2.m2,direction="both",scope=list(upper=fit1.m2,lower=fit2.m2),trace = FALSE)

summary(step.m2)
## 
## Call:
## lm(formula = cases_Diff ~ `CASE_DIFF-7` + `CASE_DIFF-14` + `CASE_DIFF-1` + 
##     `CASE_DIFF-8` + `CASE_DIFF-2` + `CASE_DIFF-9` + `CASE_DIFF-3` + 
##     `CASE_DIFF-12` + `CASE_DIFF-11` + `CASE_DIFF-13` + `CASE_DIFF-6` + 
##     `CASE_DIFF-4` + `CASE_DIFF-10` + `CASE_DIFF-5` + `DEATH_DIFF-8` + 
##     `DEATH_DIFF-7` + `DEATH_DIFF-6` + `DEATH_DIFF-5` + `DEATH_DIFF-9` + 
##     `DEATH_DIFF-10` + `DEATH_DIFF-11` + `DEATH_DIFF-12` + `DEATH_DIFF-13` + 
##     `DEATH_DIFF-14` + `DEATH_DIFF-2` + `DEATH_DIFF-1`, data = na.omit(data2))
## 
## Residuals:
##    Min     1Q Median     3Q    Max 
## -52537    -22    -13     -2  40650 
## 
## Coefficients:
##                  Estimate Std. Error  t value Pr(>|t|)    
## (Intercept)     13.198553   3.758951    3.511 0.000446 ***
## `CASE_DIFF-7`    0.464047   0.004811   96.449  < 2e-16 ***
## `CASE_DIFF-14`   0.113585   0.003660   31.035  < 2e-16 ***
## `CASE_DIFF-1`   -0.550542   0.004326 -127.254  < 2e-16 ***
## `CASE_DIFF-8`    0.338636   0.004887   69.288  < 2e-16 ***
## `CASE_DIFF-2`   -0.430428   0.004897  -87.889  < 2e-16 ***
## `CASE_DIFF-9`    0.206549   0.005083   40.636  < 2e-16 ***
## `CASE_DIFF-3`   -0.279987   0.005134  -54.536  < 2e-16 ***
## `CASE_DIFF-12`  -0.110360   0.004878  -22.622  < 2e-16 ***
## `CASE_DIFF-11`  -0.009577   0.005056   -1.894 0.058225 .  
## `CASE_DIFF-13`  -0.110529   0.004402  -25.109  < 2e-16 ***
## `CASE_DIFF-6`    0.052636   0.005030   10.465  < 2e-16 ***
## `CASE_DIFF-4`   -0.131576   0.005221  -25.200  < 2e-16 ***
## `CASE_DIFF-10`   0.106421   0.005124   20.769  < 2e-16 ***
## `CASE_DIFF-5`   -0.073953   0.005208  -14.200  < 2e-16 ***
## `DEATH_DIFF-8`   2.087797   0.109920   18.994  < 2e-16 ***
## `DEATH_DIFF-7`   1.903887   0.101099   18.832  < 2e-16 ***
## `DEATH_DIFF-6`   1.261693   0.089718   14.063  < 2e-16 ***
## `DEATH_DIFF-5`   0.656150   0.070279    9.336  < 2e-16 ***
## `DEATH_DIFF-9`   1.566417   0.113954   13.746  < 2e-16 ***
## `DEATH_DIFF-10`  1.405313   0.113072   12.428  < 2e-16 ***
## `DEATH_DIFF-11`  1.423336   0.108800   13.082  < 2e-16 ***
## `DEATH_DIFF-12`  1.063922   0.100610   10.575  < 2e-16 ***
## `DEATH_DIFF-13`  0.898552   0.089345   10.057  < 2e-16 ***
## `DEATH_DIFF-14`  0.613926   0.069571    8.824  < 2e-16 ***
## `DEATH_DIFF-2`   0.273820   0.062905    4.353 1.35e-05 ***
## `DEATH_DIFF-1`   0.192886   0.063258    3.049 0.002296 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 859.2 on 52534 degrees of freedom
## Multiple R-squared:  0.582,  Adjusted R-squared:  0.5817 
## F-statistic:  2813 on 26 and 52534 DF,  p-value: < 2.2e-16
#Compare models
anova(step.m1,step.m2)
## Analysis of Variance Table
## 
## Model 1: cases_Diff ~ `CASE_DIFF-7` + `CASE_DIFF-14` + `CASE_DIFF-1` + 
##     `CASE_DIFF-8` + `CASE_DIFF-2` + `CASE_DIFF-9` + `CASE_DIFF-3` + 
##     `CASE_DIFF-12` + `CASE_DIFF-13` + `CASE_DIFF-6` + `CASE_DIFF-4` + 
##     `CASE_DIFF-10` + `CASE_DIFF-5`
## Model 2: cases_Diff ~ `CASE_DIFF-7` + `CASE_DIFF-14` + `CASE_DIFF-1` + 
##     `CASE_DIFF-8` + `CASE_DIFF-2` + `CASE_DIFF-9` + `CASE_DIFF-3` + 
##     `CASE_DIFF-12` + `CASE_DIFF-11` + `CASE_DIFF-13` + `CASE_DIFF-6` + 
##     `CASE_DIFF-4` + `CASE_DIFF-10` + `CASE_DIFF-5` + `DEATH_DIFF-8` + 
##     `DEATH_DIFF-7` + `DEATH_DIFF-6` + `DEATH_DIFF-5` + `DEATH_DIFF-9` + 
##     `DEATH_DIFF-10` + `DEATH_DIFF-11` + `DEATH_DIFF-12` + `DEATH_DIFF-13` + 
##     `DEATH_DIFF-14` + `DEATH_DIFF-2` + `DEATH_DIFF-1`
##   Res.Df        RSS Df Sum of Sq      F    Pr(>F)    
## 1  52547 3.9167e+10                                  
## 2  52534 3.8779e+10 13 388052910 40.438 < 2.2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
Model Name Res.DF RSS Df Sum of Sq F Pr(>F)
1 52547 39.17
2 52534 38.78 13 388052910 40.438 <2.2e-16 ***
#Cases, Deaths & Population on Cases
data3 = covid.time[,c(2,6,9:36)]
fit1.m3 <- lm(cases_Diff~., data=na.omit(data3))
fit2.m3 <- lm(cases_Diff~1, data=na.omit(data3))

step.m3 = stepAIC(fit2.m3,direction="both",scope=list(upper=fit1.m3,lower=fit2.m3),trace = FALSE)

summary(step.m3)
## 
## Call:
## lm(formula = cases_Diff ~ `CASE_DIFF-7` + `CASE_DIFF-14` + `CASE_DIFF-1` + 
##     `CASE_DIFF-8` + `CASE_DIFF-2` + `CASE_DIFF-9` + `CASE_DIFF-3` + 
##     `CASE_DIFF-12` + `CASE_DIFF-11` + `CASE_DIFF-13` + `CASE_DIFF-6` + 
##     `CASE_DIFF-4` + `CASE_DIFF-10` + `CASE_DIFF-5` + `DEATH_DIFF-8` + 
##     `DEATH_DIFF-7` + `DEATH_DIFF-6` + `DEATH_DIFF-5` + `DEATH_DIFF-9` + 
##     popData2019 + `DEATH_DIFF-10` + `DEATH_DIFF-11` + `DEATH_DIFF-12` + 
##     `DEATH_DIFF-13` + `DEATH_DIFF-14` + `DEATH_DIFF-2` + `DEATH_DIFF-1`, 
##     data = na.omit(data3))
## 
## Residuals:
##    Min     1Q Median     3Q    Max 
## -52549    -22    -10      0  40623 
## 
## Coefficients:
##                   Estimate Std. Error  t value Pr(>|t|)    
## (Intercept)      9.294e+00  3.890e+00    2.389  0.01688 *  
## `CASE_DIFF-7`    4.630e-01  4.818e-03   96.112  < 2e-16 ***
## `CASE_DIFF-14`   1.133e-01  3.660e-03   30.952  < 2e-16 ***
## `CASE_DIFF-1`   -5.509e-01  4.326e-03 -127.322  < 2e-16 ***
## `CASE_DIFF-8`    3.376e-01  4.893e-03   68.997  < 2e-16 ***
## `CASE_DIFF-2`   -4.308e-01  4.898e-03  -87.965  < 2e-16 ***
## `CASE_DIFF-9`    2.056e-01  5.088e-03   40.418  < 2e-16 ***
## `CASE_DIFF-3`   -2.805e-01  5.135e-03  -54.629  < 2e-16 ***
## `CASE_DIFF-12`  -1.109e-01  4.880e-03  -22.734  < 2e-16 ***
## `CASE_DIFF-11`  -1.027e-02  5.059e-03   -2.030  0.04235 *  
## `CASE_DIFF-13`  -1.110e-01  4.403e-03  -25.202  < 2e-16 ***
## `CASE_DIFF-6`    5.172e-02  5.035e-03   10.273  < 2e-16 ***
## `CASE_DIFF-4`   -1.323e-01  5.223e-03  -25.319  < 2e-16 ***
## `CASE_DIFF-10`   1.056e-01  5.128e-03   20.597  < 2e-16 ***
## `CASE_DIFF-5`   -7.473e-02  5.211e-03  -14.341  < 2e-16 ***
## `DEATH_DIFF-8`   2.086e+00  1.099e-01   18.984  < 2e-16 ***
## `DEATH_DIFF-7`   1.902e+00  1.011e-01   18.817  < 2e-16 ***
## `DEATH_DIFF-6`   1.260e+00  8.971e-02   14.048  < 2e-16 ***
## `DEATH_DIFF-5`   6.551e-01  7.027e-02    9.323  < 2e-16 ***
## `DEATH_DIFF-9`   1.565e+00  1.139e-01   13.739  < 2e-16 ***
## popData2019      9.273e-08  2.380e-08    3.897 9.75e-05 ***
## `DEATH_DIFF-10`  1.404e+00  1.131e-01   12.422  < 2e-16 ***
## `DEATH_DIFF-11`  1.423e+00  1.088e-01   13.077  < 2e-16 ***
## `DEATH_DIFF-12`  1.064e+00  1.006e-01   10.572  < 2e-16 ***
## `DEATH_DIFF-13`  8.986e-01  8.933e-02   10.059  < 2e-16 ***
## `DEATH_DIFF-14`  6.141e-01  6.956e-02    8.828  < 2e-16 ***
## `DEATH_DIFF-2`   2.736e-01  6.290e-02    4.349 1.37e-05 ***
## `DEATH_DIFF-1`   1.924e-01  6.325e-02    3.043  0.00235 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 859.1 on 52533 degrees of freedom
## Multiple R-squared:  0.5821, Adjusted R-squared:  0.5819 
## F-statistic:  2710 on 27 and 52533 DF,  p-value: < 2.2e-16
#Compare models
anova(step.m2,step.m3)
## Analysis of Variance Table
## 
## Model 1: cases_Diff ~ `CASE_DIFF-7` + `CASE_DIFF-14` + `CASE_DIFF-1` + 
##     `CASE_DIFF-8` + `CASE_DIFF-2` + `CASE_DIFF-9` + `CASE_DIFF-3` + 
##     `CASE_DIFF-12` + `CASE_DIFF-11` + `CASE_DIFF-13` + `CASE_DIFF-6` + 
##     `CASE_DIFF-4` + `CASE_DIFF-10` + `CASE_DIFF-5` + `DEATH_DIFF-8` + 
##     `DEATH_DIFF-7` + `DEATH_DIFF-6` + `DEATH_DIFF-5` + `DEATH_DIFF-9` + 
##     `DEATH_DIFF-10` + `DEATH_DIFF-11` + `DEATH_DIFF-12` + `DEATH_DIFF-13` + 
##     `DEATH_DIFF-14` + `DEATH_DIFF-2` + `DEATH_DIFF-1`
## Model 2: cases_Diff ~ `CASE_DIFF-7` + `CASE_DIFF-14` + `CASE_DIFF-1` + 
##     `CASE_DIFF-8` + `CASE_DIFF-2` + `CASE_DIFF-9` + `CASE_DIFF-3` + 
##     `CASE_DIFF-12` + `CASE_DIFF-11` + `CASE_DIFF-13` + `CASE_DIFF-6` + 
##     `CASE_DIFF-4` + `CASE_DIFF-10` + `CASE_DIFF-5` + `DEATH_DIFF-8` + 
##     `DEATH_DIFF-7` + `DEATH_DIFF-6` + `DEATH_DIFF-5` + `DEATH_DIFF-9` + 
##     popData2019 + `DEATH_DIFF-10` + `DEATH_DIFF-11` + `DEATH_DIFF-12` + 
##     `DEATH_DIFF-13` + `DEATH_DIFF-14` + `DEATH_DIFF-2` + `DEATH_DIFF-1`
##   Res.Df        RSS Df Sum of Sq      F   Pr(>F)    
## 1  52534 3.8779e+10                                 
## 2  52533 3.8768e+10  1  11207507 15.187 9.75e-05 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
Model Name Res.DF RSS Df Sum of Sq F Pr(>F)
2 52534 38.78
3 52533 38.77 1 11207507 15.187 9.75e-05 ***
#Cases, Deaths & Population on Cases
data4 = covid.time[,c(2,7,9:36)]
fit1.m4 <- lm(cases_Diff~., data=na.omit(data4))
fit2.m4 <- lm(cases_Diff~1, data=na.omit(data4))

step.m4 = stepAIC(fit2.m4,direction="both",scope=list(upper=fit1.m4,lower=fit2.m4),trace = FALSE)

summary(step.m4)
## 
## Call:
## lm(formula = cases_Diff ~ `CASE_DIFF-7` + `CASE_DIFF-14` + `CASE_DIFF-1` + 
##     `CASE_DIFF-8` + `CASE_DIFF-2` + `CASE_DIFF-9` + `CASE_DIFF-3` + 
##     `CASE_DIFF-12` + `CASE_DIFF-11` + `CASE_DIFF-13` + `CASE_DIFF-6` + 
##     `CASE_DIFF-4` + `CASE_DIFF-10` + `CASE_DIFF-5` + `DEATH_DIFF-8` + 
##     `DEATH_DIFF-7` + `DEATH_DIFF-6` + `DEATH_DIFF-5` + `DEATH_DIFF-9` + 
##     `DEATH_DIFF-10` + `DEATH_DIFF-11` + `DEATH_DIFF-12` + `DEATH_DIFF-13` + 
##     `DEATH_DIFF-14` + `DEATH_DIFF-2` + `DEATH_DIFF-1`, data = na.omit(data4))
## 
## Residuals:
##    Min     1Q Median     3Q    Max 
## -52537    -22    -13     -2  40650 
## 
## Coefficients:
##                  Estimate Std. Error  t value Pr(>|t|)    
## (Intercept)     13.198553   3.758951    3.511 0.000446 ***
## `CASE_DIFF-7`    0.464047   0.004811   96.449  < 2e-16 ***
## `CASE_DIFF-14`   0.113585   0.003660   31.035  < 2e-16 ***
## `CASE_DIFF-1`   -0.550542   0.004326 -127.254  < 2e-16 ***
## `CASE_DIFF-8`    0.338636   0.004887   69.288  < 2e-16 ***
## `CASE_DIFF-2`   -0.430428   0.004897  -87.889  < 2e-16 ***
## `CASE_DIFF-9`    0.206549   0.005083   40.636  < 2e-16 ***
## `CASE_DIFF-3`   -0.279987   0.005134  -54.536  < 2e-16 ***
## `CASE_DIFF-12`  -0.110360   0.004878  -22.622  < 2e-16 ***
## `CASE_DIFF-11`  -0.009577   0.005056   -1.894 0.058225 .  
## `CASE_DIFF-13`  -0.110529   0.004402  -25.109  < 2e-16 ***
## `CASE_DIFF-6`    0.052636   0.005030   10.465  < 2e-16 ***
## `CASE_DIFF-4`   -0.131576   0.005221  -25.200  < 2e-16 ***
## `CASE_DIFF-10`   0.106421   0.005124   20.769  < 2e-16 ***
## `CASE_DIFF-5`   -0.073953   0.005208  -14.200  < 2e-16 ***
## `DEATH_DIFF-8`   2.087797   0.109920   18.994  < 2e-16 ***
## `DEATH_DIFF-7`   1.903887   0.101099   18.832  < 2e-16 ***
## `DEATH_DIFF-6`   1.261693   0.089718   14.063  < 2e-16 ***
## `DEATH_DIFF-5`   0.656150   0.070279    9.336  < 2e-16 ***
## `DEATH_DIFF-9`   1.566417   0.113954   13.746  < 2e-16 ***
## `DEATH_DIFF-10`  1.405313   0.113072   12.428  < 2e-16 ***
## `DEATH_DIFF-11`  1.423336   0.108800   13.082  < 2e-16 ***
## `DEATH_DIFF-12`  1.063922   0.100610   10.575  < 2e-16 ***
## `DEATH_DIFF-13`  0.898552   0.089345   10.057  < 2e-16 ***
## `DEATH_DIFF-14`  0.613926   0.069571    8.824  < 2e-16 ***
## `DEATH_DIFF-2`   0.273820   0.062905    4.353 1.35e-05 ***
## `DEATH_DIFF-1`   0.192886   0.063258    3.049 0.002296 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 859.2 on 52534 degrees of freedom
## Multiple R-squared:  0.582,  Adjusted R-squared:  0.5817 
## F-statistic:  2813 on 26 and 52534 DF,  p-value: < 2.2e-16
#Compare models
anova(step.m3,step.m4)
## Analysis of Variance Table
## 
## Model 1: cases_Diff ~ `CASE_DIFF-7` + `CASE_DIFF-14` + `CASE_DIFF-1` + 
##     `CASE_DIFF-8` + `CASE_DIFF-2` + `CASE_DIFF-9` + `CASE_DIFF-3` + 
##     `CASE_DIFF-12` + `CASE_DIFF-11` + `CASE_DIFF-13` + `CASE_DIFF-6` + 
##     `CASE_DIFF-4` + `CASE_DIFF-10` + `CASE_DIFF-5` + `DEATH_DIFF-8` + 
##     `DEATH_DIFF-7` + `DEATH_DIFF-6` + `DEATH_DIFF-5` + `DEATH_DIFF-9` + 
##     popData2019 + `DEATH_DIFF-10` + `DEATH_DIFF-11` + `DEATH_DIFF-12` + 
##     `DEATH_DIFF-13` + `DEATH_DIFF-14` + `DEATH_DIFF-2` + `DEATH_DIFF-1`
## Model 2: cases_Diff ~ `CASE_DIFF-7` + `CASE_DIFF-14` + `CASE_DIFF-1` + 
##     `CASE_DIFF-8` + `CASE_DIFF-2` + `CASE_DIFF-9` + `CASE_DIFF-3` + 
##     `CASE_DIFF-12` + `CASE_DIFF-11` + `CASE_DIFF-13` + `CASE_DIFF-6` + 
##     `CASE_DIFF-4` + `CASE_DIFF-10` + `CASE_DIFF-5` + `DEATH_DIFF-8` + 
##     `DEATH_DIFF-7` + `DEATH_DIFF-6` + `DEATH_DIFF-5` + `DEATH_DIFF-9` + 
##     `DEATH_DIFF-10` + `DEATH_DIFF-11` + `DEATH_DIFF-12` + `DEATH_DIFF-13` + 
##     `DEATH_DIFF-14` + `DEATH_DIFF-2` + `DEATH_DIFF-1`
##   Res.Df        RSS Df Sum of Sq      F   Pr(>F)    
## 1  52533 3.8768e+10                                 
## 2  52534 3.8779e+10 -1 -11207507 15.187 9.75e-05 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
Model Name Res.DF RSS Df Sum of Sq F Pr(>F)
3 52533 38.77
4 52534 38.78 -1 -11207507 15.187 9.75e-05 ***

Final Model

summary(step.m3)
## 
## Call:
## lm(formula = cases_Diff ~ `CASE_DIFF-7` + `CASE_DIFF-14` + `CASE_DIFF-1` + 
##     `CASE_DIFF-8` + `CASE_DIFF-2` + `CASE_DIFF-9` + `CASE_DIFF-3` + 
##     `CASE_DIFF-12` + `CASE_DIFF-11` + `CASE_DIFF-13` + `CASE_DIFF-6` + 
##     `CASE_DIFF-4` + `CASE_DIFF-10` + `CASE_DIFF-5` + `DEATH_DIFF-8` + 
##     `DEATH_DIFF-7` + `DEATH_DIFF-6` + `DEATH_DIFF-5` + `DEATH_DIFF-9` + 
##     popData2019 + `DEATH_DIFF-10` + `DEATH_DIFF-11` + `DEATH_DIFF-12` + 
##     `DEATH_DIFF-13` + `DEATH_DIFF-14` + `DEATH_DIFF-2` + `DEATH_DIFF-1`, 
##     data = na.omit(data3))
## 
## Residuals:
##    Min     1Q Median     3Q    Max 
## -52549    -22    -10      0  40623 
## 
## Coefficients:
##                   Estimate Std. Error  t value Pr(>|t|)    
## (Intercept)      9.294e+00  3.890e+00    2.389  0.01688 *  
## `CASE_DIFF-7`    4.630e-01  4.818e-03   96.112  < 2e-16 ***
## `CASE_DIFF-14`   1.133e-01  3.660e-03   30.952  < 2e-16 ***
## `CASE_DIFF-1`   -5.509e-01  4.326e-03 -127.322  < 2e-16 ***
## `CASE_DIFF-8`    3.376e-01  4.893e-03   68.997  < 2e-16 ***
## `CASE_DIFF-2`   -4.308e-01  4.898e-03  -87.965  < 2e-16 ***
## `CASE_DIFF-9`    2.056e-01  5.088e-03   40.418  < 2e-16 ***
## `CASE_DIFF-3`   -2.805e-01  5.135e-03  -54.629  < 2e-16 ***
## `CASE_DIFF-12`  -1.109e-01  4.880e-03  -22.734  < 2e-16 ***
## `CASE_DIFF-11`  -1.027e-02  5.059e-03   -2.030  0.04235 *  
## `CASE_DIFF-13`  -1.110e-01  4.403e-03  -25.202  < 2e-16 ***
## `CASE_DIFF-6`    5.172e-02  5.035e-03   10.273  < 2e-16 ***
## `CASE_DIFF-4`   -1.323e-01  5.223e-03  -25.319  < 2e-16 ***
## `CASE_DIFF-10`   1.056e-01  5.128e-03   20.597  < 2e-16 ***
## `CASE_DIFF-5`   -7.473e-02  5.211e-03  -14.341  < 2e-16 ***
## `DEATH_DIFF-8`   2.086e+00  1.099e-01   18.984  < 2e-16 ***
## `DEATH_DIFF-7`   1.902e+00  1.011e-01   18.817  < 2e-16 ***
## `DEATH_DIFF-6`   1.260e+00  8.971e-02   14.048  < 2e-16 ***
## `DEATH_DIFF-5`   6.551e-01  7.027e-02    9.323  < 2e-16 ***
## `DEATH_DIFF-9`   1.565e+00  1.139e-01   13.739  < 2e-16 ***
## popData2019      9.273e-08  2.380e-08    3.897 9.75e-05 ***
## `DEATH_DIFF-10`  1.404e+00  1.131e-01   12.422  < 2e-16 ***
## `DEATH_DIFF-11`  1.423e+00  1.088e-01   13.077  < 2e-16 ***
## `DEATH_DIFF-12`  1.064e+00  1.006e-01   10.572  < 2e-16 ***
## `DEATH_DIFF-13`  8.986e-01  8.933e-02   10.059  < 2e-16 ***
## `DEATH_DIFF-14`  6.141e-01  6.956e-02    8.828  < 2e-16 ***
## `DEATH_DIFF-2`   2.736e-01  6.290e-02    4.349 1.37e-05 ***
## `DEATH_DIFF-1`   1.924e-01  6.325e-02    3.043  0.00235 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 859.1 on 52533 degrees of freedom
## Multiple R-squared:  0.5821, Adjusted R-squared:  0.5819 
## F-statistic:  2710 on 27 and 52533 DF,  p-value: < 2.2e-16

Model Presenting

stargazer(step.m1, step.m2, title = "Results of Model 1 & 2", align = T,type = "text" )
## 
## Results of Model 1 & 2
## ===============================================================================
##                                         Dependent variable:                    
##                     -----------------------------------------------------------
##                                             cases_Diff                         
##                                  (1)                           (2)             
## -------------------------------------------------------------------------------
## `CASE_DIFF-7`                 0.489***                      0.464***           
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-14`                0.119***                      0.114***           
##                                (0.004)                       (0.004)           
##                                                                                
## `CASE_DIFF-1`                 -0.543***                     -0.551***          
##                                (0.004)                       (0.004)           
##                                                                                
## `CASE_DIFF-8`                 0.363***                      0.339***           
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-2`                 -0.423***                     -0.430***          
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-9`                 0.222***                      0.207***           
##                                (0.004)                       (0.005)           
##                                                                                
## `CASE_DIFF-3`                 -0.277***                     -0.280***          
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-12`                -0.106***                     -0.110***          
##                                (0.004)                       (0.005)           
##                                                                                
## `CASE_DIFF-11`                                               -0.010*           
##                                                              (0.005)           
##                                                                                
## `CASE_DIFF-13`                -0.103***                     -0.111***          
##                                (0.004)                       (0.004)           
##                                                                                
## `CASE_DIFF-6`                 0.068***                      0.053***           
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-4`                 -0.132***                     -0.132***          
##                                (0.004)                       (0.005)           
##                                                                                
## `CASE_DIFF-10`                0.116***                      0.106***           
##                                (0.004)                       (0.005)           
##                                                                                
## `CASE_DIFF-5`                 -0.066***                     -0.074***          
##                                (0.005)                       (0.005)           
##                                                                                
## `DEATH_DIFF-8`                                              2.088***           
##                                                              (0.110)           
##                                                                                
## `DEATH_DIFF-7`                                              1.904***           
##                                                              (0.101)           
##                                                                                
## `DEATH_DIFF-6`                                              1.262***           
##                                                              (0.090)           
##                                                                                
## `DEATH_DIFF-5`                                              0.656***           
##                                                              (0.070)           
##                                                                                
## `DEATH_DIFF-9`                                              1.566***           
##                                                              (0.114)           
##                                                                                
## `DEATH_DIFF-10`                                             1.405***           
##                                                              (0.113)           
##                                                                                
## `DEATH_DIFF-11`                                             1.423***           
##                                                              (0.109)           
##                                                                                
## `DEATH_DIFF-12`                                             1.064***           
##                                                              (0.101)           
##                                                                                
## `DEATH_DIFF-13`                                             0.899***           
##                                                              (0.089)           
##                                                                                
## `DEATH_DIFF-14`                                             0.614***           
##                                                              (0.070)           
##                                                                                
## `DEATH_DIFF-2`                                              0.274***           
##                                                              (0.063)           
##                                                                                
## `DEATH_DIFF-1`                                              0.193***           
##                                                              (0.063)           
##                                                                                
## Constant                      14.152***                     13.199***          
##                                (3.776)                       (3.759)           
##                                                                                
## -------------------------------------------------------------------------------
## Observations                   52,561                        52,561            
## R2                              0.578                         0.582            
## Adjusted R2                     0.578                         0.582            
## Residual Std. Error     863.350 (df = 52547)          859.169 (df = 52534)     
## F Statistic         5,531.152*** (df = 13; 52547) 2,812.779*** (df = 26; 52534)
## ===============================================================================
## Note:                                               *p<0.1; **p<0.05; ***p<0.01
stargazer(step.m3, step.m4, title = "Results of Model 3 & 4", align = T,type = "text" )
## 
## Results of Model 3 & 4
## ===============================================================================
##                                         Dependent variable:                    
##                     -----------------------------------------------------------
##                                             cases_Diff                         
##                                  (1)                           (2)             
## -------------------------------------------------------------------------------
## `CASE_DIFF-7`                 0.463***                      0.464***           
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-14`                0.113***                      0.114***           
##                                (0.004)                       (0.004)           
##                                                                                
## `CASE_DIFF-1`                 -0.551***                     -0.551***          
##                                (0.004)                       (0.004)           
##                                                                                
## `CASE_DIFF-8`                 0.338***                      0.339***           
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-2`                 -0.431***                     -0.430***          
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-9`                 0.206***                      0.207***           
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-3`                 -0.281***                     -0.280***          
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-12`                -0.111***                     -0.110***          
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-11`                -0.010**                       -0.010*           
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-13`                -0.111***                     -0.111***          
##                                (0.004)                       (0.004)           
##                                                                                
## `CASE_DIFF-6`                 0.052***                      0.053***           
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-4`                 -0.132***                     -0.132***          
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-10`                0.106***                      0.106***           
##                                (0.005)                       (0.005)           
##                                                                                
## `CASE_DIFF-5`                 -0.075***                     -0.074***          
##                                (0.005)                       (0.005)           
##                                                                                
## `DEATH_DIFF-8`                2.086***                      2.088***           
##                                (0.110)                       (0.110)           
##                                                                                
## `DEATH_DIFF-7`                1.902***                      1.904***           
##                                (0.101)                       (0.101)           
##                                                                                
## `DEATH_DIFF-6`                1.260***                      1.262***           
##                                (0.090)                       (0.090)           
##                                                                                
## `DEATH_DIFF-5`                0.655***                      0.656***           
##                                (0.070)                       (0.070)           
##                                                                                
## `DEATH_DIFF-9`                1.565***                      1.566***           
##                                (0.114)                       (0.114)           
##                                                                                
## popData2019                  0.00000***                                        
##                               (0.00000)                                        
##                                                                                
## `DEATH_DIFF-10`               1.404***                      1.405***           
##                                (0.113)                       (0.113)           
##                                                                                
## `DEATH_DIFF-11`               1.423***                      1.423***           
##                                (0.109)                       (0.109)           
##                                                                                
## `DEATH_DIFF-12`               1.064***                      1.064***           
##                                (0.101)                       (0.101)           
##                                                                                
## `DEATH_DIFF-13`               0.899***                      0.899***           
##                                (0.089)                       (0.089)           
##                                                                                
## `DEATH_DIFF-14`               0.614***                      0.614***           
##                                (0.070)                       (0.070)           
##                                                                                
## `DEATH_DIFF-2`                0.274***                      0.274***           
##                                (0.063)                       (0.063)           
##                                                                                
## `DEATH_DIFF-1`                0.192***                      0.193***           
##                                (0.063)                       (0.063)           
##                                                                                
## Constant                       9.294**                      13.199***          
##                                (3.890)                       (3.759)           
##                                                                                
## -------------------------------------------------------------------------------
## Observations                   52,561                        52,561            
## R2                              0.582                         0.582            
## Adjusted R2                     0.582                         0.582            
## Residual Std. Error     859.053 (df = 52533)          859.169 (df = 52534)     
## F Statistic         2,709.896*** (df = 27; 52533) 2,812.779*** (df = 26; 52534)
## ===============================================================================
## Note:                                               *p<0.1; **p<0.05; ***p<0.01
stargazer(step.m1, step.m2, step.m3, title = "Results of Model 1 & 2 & 3", align = T,type = "text")
## 
## Results of Model 1 & 2 & 3
## =============================================================================================================
##                                                        Dependent variable:                                   
##                     -----------------------------------------------------------------------------------------
##                                                            cases_Diff                                        
##                                  (1)                           (2)                           (3)             
## -------------------------------------------------------------------------------------------------------------
## `CASE_DIFF-7`                 0.489***                      0.464***                      0.463***           
##                                (0.005)                       (0.005)                       (0.005)           
##                                                                                                              
## `CASE_DIFF-14`                0.119***                      0.114***                      0.113***           
##                                (0.004)                       (0.004)                       (0.004)           
##                                                                                                              
## `CASE_DIFF-1`                 -0.543***                     -0.551***                     -0.551***          
##                                (0.004)                       (0.004)                       (0.004)           
##                                                                                                              
## `CASE_DIFF-8`                 0.363***                      0.339***                      0.338***           
##                                (0.005)                       (0.005)                       (0.005)           
##                                                                                                              
## `CASE_DIFF-2`                 -0.423***                     -0.430***                     -0.431***          
##                                (0.005)                       (0.005)                       (0.005)           
##                                                                                                              
## `CASE_DIFF-9`                 0.222***                      0.207***                      0.206***           
##                                (0.004)                       (0.005)                       (0.005)           
##                                                                                                              
## `CASE_DIFF-3`                 -0.277***                     -0.280***                     -0.281***          
##                                (0.005)                       (0.005)                       (0.005)           
##                                                                                                              
## `CASE_DIFF-12`                -0.106***                     -0.110***                     -0.111***          
##                                (0.004)                       (0.005)                       (0.005)           
##                                                                                                              
## `CASE_DIFF-11`                                               -0.010*                      -0.010**           
##                                                              (0.005)                       (0.005)           
##                                                                                                              
## `CASE_DIFF-13`                -0.103***                     -0.111***                     -0.111***          
##                                (0.004)                       (0.004)                       (0.004)           
##                                                                                                              
## `CASE_DIFF-6`                 0.068***                      0.053***                      0.052***           
##                                (0.005)                       (0.005)                       (0.005)           
##                                                                                                              
## `CASE_DIFF-4`                 -0.132***                     -0.132***                     -0.132***          
##                                (0.004)                       (0.005)                       (0.005)           
##                                                                                                              
## `CASE_DIFF-10`                0.116***                      0.106***                      0.106***           
##                                (0.004)                       (0.005)                       (0.005)           
##                                                                                                              
## `CASE_DIFF-5`                 -0.066***                     -0.074***                     -0.075***          
##                                (0.005)                       (0.005)                       (0.005)           
##                                                                                                              
## `DEATH_DIFF-8`                                              2.088***                      2.086***           
##                                                              (0.110)                       (0.110)           
##                                                                                                              
## `DEATH_DIFF-7`                                              1.904***                      1.902***           
##                                                              (0.101)                       (0.101)           
##                                                                                                              
## `DEATH_DIFF-6`                                              1.262***                      1.260***           
##                                                              (0.090)                       (0.090)           
##                                                                                                              
## `DEATH_DIFF-5`                                              0.656***                      0.655***           
##                                                              (0.070)                       (0.070)           
##                                                                                                              
## `DEATH_DIFF-9`                                              1.566***                      1.565***           
##                                                              (0.114)                       (0.114)           
##                                                                                                              
## popData2019                                                                              0.00000***          
##                                                                                           (0.00000)          
##                                                                                                              
## `DEATH_DIFF-10`                                             1.405***                      1.404***           
##                                                              (0.113)                       (0.113)           
##                                                                                                              
## `DEATH_DIFF-11`                                             1.423***                      1.423***           
##                                                              (0.109)                       (0.109)           
##                                                                                                              
## `DEATH_DIFF-12`                                             1.064***                      1.064***           
##                                                              (0.101)                       (0.101)           
##                                                                                                              
## `DEATH_DIFF-13`                                             0.899***                      0.899***           
##                                                              (0.089)                       (0.089)           
##                                                                                                              
## `DEATH_DIFF-14`                                             0.614***                      0.614***           
##                                                              (0.070)                       (0.070)           
##                                                                                                              
## `DEATH_DIFF-2`                                              0.274***                      0.274***           
##                                                              (0.063)                       (0.063)           
##                                                                                                              
## `DEATH_DIFF-1`                                              0.193***                      0.192***           
##                                                              (0.063)                       (0.063)           
##                                                                                                              
## Constant                      14.152***                     13.199***                      9.294**           
##                                (3.776)                       (3.759)                       (3.890)           
##                                                                                                              
## -------------------------------------------------------------------------------------------------------------
## Observations                   52,561                        52,561                        52,561            
## R2                              0.578                         0.582                         0.582            
## Adjusted R2                     0.578                         0.582                         0.582            
## Residual Std. Error     863.350 (df = 52547)          859.169 (df = 52534)          859.053 (df = 52533)     
## F Statistic         5,531.152*** (df = 13; 52547) 2,812.779*** (df = 26; 52534) 2,709.896*** (df = 27; 52533)
## =============================================================================================================
## Note:                                                                             *p<0.1; **p<0.05; ***p<0.01